In assembly of rotary machines, such as gas turbine engines, many measurements of parts are taken to determine assembly orientation to minimize vibration and run-out. Typical measurement apparatuses are capable of performing only relative measurements, such as eccentricity and roundness. U.S. Pat. Nos. 8,219,353 and 8,538,725 (both by assignee and herein incorporated by reference) provide apparatuses and methods for performing absolute diameter measurements.